Obsidian
Volcanic Glass (SiO2)
Category
Browse glass specimens identified by the Rock Identifier community.
Obsidian
Volcanic Glass (SiO2)
Obsidian
Obsidian (Volcanic Glass)
Silver Sheen Obsidian
Volcanic Glass (SiO2)
Black Obsidian
Volcanic Glass (SiO2)
Obsidian
Volcanic Glass (SiO2)
Pumice
Vesicular volcanic glass
Obsidian
Volcanic Glass (SiO2)
Obsidian
Obsidian (Volcanic Glass)
Obsidian
Volcanic Glass (SiO2)
Obsidian
Volcanic Glass (SiO2)
Obsidian (Black Obsidian)
Obsidian (Volcanic Glass)
Obsidian
Volcanic Glass (SiO2)
Black Obsidian
Obsidian (Volcanic Glass)
Aura Quartz (Titanium/Rainbow Quartz)
SiO2 (Silicon Dioxide) with metallic coating
Polished dark pebble, likely basalt or chert
Basalt (mafic volcanic rock), possibly microcrystalline chert
Chert (Iron-stained)
Microcrystalline silica (SiO2) with Hematite/Limonite
Chert (Jasper variety)
Silicon Dioxide (SiO2)
Chert
Chert (SiO2)
Milky Quartz Pebble with Chert
Silicon Dioxide (SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Chert (Flint)
Chert (Microcrystalline or Cryptocrystalline Quartz, SiO2)
Chert (Flint)
Silicon Dioxide (SiO2)
Citrine or Yellow Quartz
Silicon Dioxide (SiO2) with iron impurities
Smoky Quartz
Silicon Dioxide (SiO2) with aluminum impurities
Chert (Iron-stained)
Chert (SiO2)
Chert (Green River Chert)
Microcrystalline Quartz (SiO2)
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Tumbled yellow quartz (likely citrine or iron-stained quartz)
Quartz, silicon dioxide (SiO₂), yellow coloration from iron impurities
Faceted yellow-brown gemstone earring
Likely citrine (quartz, SiO₂), though treated quartz or synthetic glass cannot be confirmed from the image
Slag (Industrial Byproduct)
Ferro-silicate glass (Slag)
Black obsidian
Volcanic glass (mostly rhyolitic silica glass; SiO₂-rich)
Tumbled black obsidian (likely)
Volcanic glass; chiefly silica-rich rhyolitic glass (SiO₂)
Obsidian (likely snowflake or smoky obsidian fragment)
Volcanic glass; predominantly rhyolitic silica glass (SiO₂-rich)
Blue Goldstone
Synthetic Aventurescent Glass (Cobalt-doped soda-lime glass)
Blue Goldstone
Aventurine glass (Synthetic borosilicate glass with cobalt and metallic inclusions)
Rose Quartz
Silicon dioxide (SiO2) with trace impurities of titanium, iron, or manganese
Chert (Flint)
Silicon Dioxide (SiO2)
Quartz (Iron-stained)
Silicon Dioxide (SiO2)
Pink Quartz
Silicon Dioxide (SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Chert or flint fragment
Microcrystalline quartz (SiO₂), possibly iron-stained chert